South African Journal of Chemistry
On-line version ISSN 1996-840X
POPPLEWELL, Wendy L. et al. Euphorbias of South Africa: Two new phorbol esters from Euphorbia bothae. S.Afr.j.chem. (Online) [online]. 2010, vol.63, pp. 175-179. ISSN 1996-840X.
Two known phorbol esters, 12-deoxyphorbol-13-isobutyrate-20-acetate (1) and 12-deoxyphorbol-13-(2-methylbutyrate)-20-acetate (2), and two new phorbol esters, 12-deoxyphorbol-13-isobutyrate-16-angelate-20-acetate (3) and 12-deoxyphorbol-13-(2-methylbutyrate)-16-angelate-20-acetate (4), were isolated from the endemic South African plant Euphorbia bothae. Standard spectroscopic techniques were used to elucidate the structures of all four compounds. The interaction of 1-4 with opioid receptors was explored in an attempt to explain the unexplained stupor occasionally observed in herbivores browsing on E. bothae.
Keywords : Euphorbia bothae; Euphorbiaceae; phorbol ester; opioid receptor.